The assassination of Imad Mougnieh has ended the quarter-century career of a senior military operative – or "terrorist," to his enemies in the United States and Israel – of Lebanon's Hizbollah or "Party of God".

The United States had credited Mougnieh with the 1983 bombing of its embassy in Beirut and the destruction of the US Marine headquarters later that year, the hijacking of TWA flight 847 in 1985 and the kidnappings of dozens of American citizens in Lebanon throughout the 1980s. Israel blamed him for the suicide bombing that levelled its military command centre in Tyre, south Lebanon, in 1982 and the attacks on its embassy in Buenos Aires in 1992 and a Jewish centre there in 1994. Although both the United States and Israel denied responsibility for Mougnieh's death, both countries expressed satisfaction at his demise.

Born to a Shiite Muslim peasant family in the south Lebanese village of Tayr Dibbis, near Tyre, in 1962, Mougnieh was the eldest of three brothers. The family moved to the slums that were growing up around south-western Beirut with the influx of refugees from the conflict between Israel and the Palestine Liberation Organisation in the early 1970s. The move did not, however, keep young Imad out of the fighting. At an early age, he joined Yasser Arafat's Fatah commando group. He worked with Arafat's military chief Khalil Wazir (Abu Jihad), in operations along Lebanon's border with Israel. In common with many of the other Lebanese Shiites who had trained with Fatah, Mougnieh joined the Amal group, whose head was the charismatic Shiite clergyman Imam Musa Sadr.

Following the Israeli invasion of Lebanon in June 1982, many Shiite Muslims pressed for a more determined armed opposition to Israeli occupation than Amal was offering. Some Shiite activists, assisted by Iranian Revolutionary Guards, formed Hizbollah as a clandestine guerrilla force that attacked both Israelis and the American and French units of the Multinational Force.

One of the first operations was a suicide bombing at Israel's military headquarters in Tyre in the summer of 1982. Although the US and Israel later claimed that Mougnieh was behind the bombing, many Lebanese observers doubted that a 21-year-old would be granted the authority to run an action of such importance. The same may be said of American claims that Mougnieh destroyed the US embassy and Marine barracks in Beirut a year later, when Mougnieh was 22. However, in the years that followed, almost all major Hizbollah operations were blamed by Israel and the US on Mougnieh. This made him one of the "terrorists" most wanted by the intelligence services of both Israel and the US.

When Hizbollah operatives hijacked a TWA airliner in June 1985 and murdered one of its American passengers, a Navy diver named Robert Dean Stethem, the US indicted Mougnieh and actively sought to bring him to justice for the crime. In the meantime, however, America negotiated through Syria for the release of the hostages from the plane and Israel then released more than 700 Shiite civilians it had taken illegally to a prison in Israel.

The rationale for the massacre of Israelis in Argentina in 1992 and 1994 remains more obscure. These were two rare instances of Hizbollah outrages outside Lebanon and its border area with Israel.

Mougnieh's name was more clearly associated with the Hizbollah policy of kidnapping foreigners in Lebanon between 1982 and 1990. Its first hostage was David Dodge, the acting president of the American University of Beirut who was seized in August 1982 in response to the disappearance of five Iranian diplomats in the Christian area of Lebanon a few days before. Dodge was held for almost a year, part of that time in Iran, until the Syrian President Hafez al-Assad brokered his release as a favour to ingratiate himself with the United States.

Other kidnappings followed. Among the Britons taken were John McCarthy, Brian Keenan and Terry Waite. The longest held western captive was the Associated Press bureau chief Terry Anderson, taken in 1985 and not released until December 1991. Hizbollah responsibility and Iranian direction of most of the kidnappings was rarely in doubt, as became clear when the Reagan administration's policy of giving anti-tank weapons to Iran in exchange for American hostages became public knowledge in 1986, as the Iran-Contra scandal.

When I was among those held captive in 1987 for two months, a message from the Iranian foreign ministry to the Syrian embassy in Damascus made clear that there was a direct order from Iran to Hizbollah to capture an American in Lebanon. Mougnieh's name came up again and again in the context of directing the kidnappings that Hizbollah still officially denies it undertook, although hard evidence against Mougnieh has yet to be presented to the courts or the press.

Mougnieh was elusive, known to many of his comrades in south Lebanon only as Abu Radwan (a nom de guerre meaning, roughly, "Father of Pleasure", in the sense of spiritual happiness). Car bombs killed his two younger brothers, Fouad, and – at Fouad's funeral – Jihad, in what were believed to have been attempts on Mougnieh himself. In the village of Tayr Dibba, where he was born, people told Beirut's Daily Star that Mougnieh paid a secret visit to the village when his mother died there two years ago. Otherwise, he was rarely seen.

Some of his followers called him as-Sahir, the magician, for his skill at hitting the Israelis while avoiding death himself. Insiders said that Mougnieh actively led Hizbollah fighters in their successful defence against Israel's most recent invasion of Lebanon in the summer of 2006. Otherwise, he was believed to have spent much of his time in two countries where he had reason to believe Israel could not reach him, Iran and Syria.

The assassination took place using a method Mougnieh himself may have perfected in his campaign against the Israelis and Americans in Lebanon: the car bomb. On Tuesday night, while Mougnieh was walking towards or getting into his Mitsubishi Pajero in the middle-class Kfar Sousse quarter in Damascus, a blast killed him and at least one bystander.

Syria, Iran and Hizbollah blamed Israel, but Israel officially denied it. Dany Yatom, the former head of Mossad, told Israeli radio, "He [Mougnieh] was not only being targeted by Israel, but also by Americans and many other parties . . . He behaved with extreme caution for many years. It was impossible even to obtain his picture. He never appeared [in] or spoke to the media . . . He behaved with extreme caution, and that was the reason it was difficult to get to him for so many years."

Someone finally got to him. Whether Israel, which had the motive and probably the means, was responsible may have to await publication of the next Mossad chief's memoirs.